The invention relates to a pull-out guide for drawers or the like, comprising a body rail, a drawer rail, and a center rail which runs differentially between these two and is guided in two rolling body carriages, one of which is supported in the body rail and the other is supported in the drawer rail, wherein the center rail comprises a toothed wheel and the two rolling body carriages each comprise one toothed rack that meshes with the toothed wheel and wherein, when the pull-out guide is completely pulled out, the drawer rail is pulled out beyond the body rail.
The given installation depth of a piece of furniture is just sufficient for full extension of the drawer when the guide lengths are utilized in a standard way. A required increase in length of extension of the drawer without increasing the installation depth is realized in practice by an over-extension, whereby the drawer rail is pulled out beyond the body rail. The problems of overcoming the movement of drawer rail and body rail away from each other and maintaining the differential or synchronization of these two rails represent the main difficulty in addition to the decreasing stability, since the remaining section is only overcome by the center rail.
In accordance with prior art, over-extensions of drawer rails and body rails that move away from each other and maintenance of synchronization are realized in a complex manner via strings, foldable support elements, foldable toothed racks and the like. Takeover of synchronization in the over-extended section is conventionally also realized by a plurality of toothed wheels.